Process in the temporary retarding and suspending the setting of dental cements.



J. W. SMITH.

PROCESS IN THE TEMPORARY RETARDING AND SU SPENDING THE SETTING 0F DENTAL CEMENTS.

APPLICATION FILED FEB. 23, 1918.

1,210,555, Patented Jan. 2, 1917.

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i EVE JULIUS W. SMITH, OF MADISON, MINNESOTA.

PROCESS IN THE'TEMPORARY RETARDING AND SUSPENDING THE SETTING OF DENTAL CEMEN'IS.

Specification of Letters Patent.- Patented Jan, 2, 1917,

Application filed February 23, 1916. Serial No. 79,966.

To all whom it may concern:

Be it known that I, JULIUs W. SMITH, a citizen of the United States, residing in Madison, in the county of Lao qui Parle and State of Minnesota, have invented a New Process in the Temporary Retarding and suspending the Setting of Dental Gements, of which the following is a specificat ntemporarily retarding and suspending the setting of dental cements by means of mixing the cement powder and liquid together in a cold glass mortar or other suitable receptacle, at a temperature below the normal chemical combining point, thereby getting a denser mixture of powder in the same amount of liquid and giving the operator more time to thoroughly mix the liquid and powder and having practically all of the cement setting or chemical combining take place in the tooth.

This process is especially adapted to the synthetic or quick setting cements, while, however, it gives equally good results with any of the dental cements. With this process no evaporation of the liquid or chemical Y combination will take place while mixing the same with the powder, as is the case in the use of the old method with the slab at room temperature, and it will, therefore, be seen that a great deal more powder can be incorporated with the same amount of liquid, giv ing a better consistency to the mass and when it sets in the tooth it will become very hard and durable.

To assist in carrying out this process, a cooling apparatus A, as is illustrated in the accompanying drawing can be used.

The apparatus A, has a body portion B, and an inlet pipe 0, is screwed into the bottom of the same, which is adapted to be connected with a carbon tank, not shown, in any suitable manner. The pipe C connects with a chamber E, through the small hole D, thus allowing carbon dioxid gas to pass from the pipe C3 into chamber E, and out through a series of holes F, which are formed in the side wall of the body B, near the top of the apparatus. A second chamber G, is formed in the body B and is separated from the chamber E, by the thin wall I-I; extending down into the chamber G, and

This invention relates to the process of,

ess, a certain amount of water is put into the chamber G, and the mortar I screwed into place, and then carbon dioxid gas is passed through the chamber E, thereby freezing the water in the chamber G, about the mortar I. The proper amount of liquid is then dropped into the mortar I and the powder added in successive stages. Each addition of powder being thoroughly incorporated or mixed with the liquid, using a suitable instrument for mixing, until the proper consistency is reached. The mixed mass can be kept in this cold mortar for some time before using in the cavity of the tooth, without affecting or setting the same, thus giving the. dentist plenty of time to make the filling.

It has, for a long time, been the aim of dentistry to present the setting or chemical combination of dental cement while being mixed or spatulated and have the setting or combination take place in the cavity and by this process I accomplish this end, giving a filling which is durable for general use and even to be preferred as it closely resem bles the natural teeth.

By the use of an apparatus illustrated in the drawing, I prevent condensation of atmospheric moisture and subsequent collecting of the moisture upon the chilled surface where the powder and liquid are brought together, which would change the formula or the consistency of the cement. This apparatus excludes the flow of air into the mortar by reason of the fact that a small amount of air in the mortar is cold and heavy and cannot be displaced by the lighter and warmer air above. As the air in the mortar is warmed and rises, it will flow over the outer edge of the apparatus and deposit moisture outside of the mortar itself, thus preventing any moisture from the atmosphere from entering the mixture and changing the density of the cement.

In the old method of using a mixing slab and spatula, if cooled, the slab is bound to collect a certain amount of humidity from the air in the room and therefore this method is not practical.

It is obvious that the apparatus shown in the drawing is only illustrative and I believe that my process can be carried out by other means of apparatus within the scope of the following claims.

What I claim is:

1. The process of temporarily retarding and suspending the setting of dental cements, consisting in keeping the powder and cement liquid ingredients of the cement at a temperature below the chemical combining point while being mixed substantially as described. 7

2. The process of temporarily retarding and suspending the setting of dental cements, consisting in mixing the cement powder and liquid at a low temperature so as to prevent the chemical combination in the powder and liquid while being mixed and to be held at a low temperature until it Copies of this patent may be obtained for five cents each, by addressing JULIUS W. SMITH.

Witnesses:

-WALTER G. BRANDT,

HOWARD L. FISCHER.

Washington, D. G.

the Commissioner of Ratents, 

